Cream cheese is a soft, mild acid-coagulated uncured cheese made from a mixture of cream and milk. Cream cheese is stored under refrigeration conditions and the body of cream cheese is smooth and butter-like. The texture and body of cream cheese at refrigeration temperatures is such that the cream cheese can be sliced and spread. In making cream cheese, sweet whole milk and/or skim milk and sweet cream are blended in pre-selected proportions to form a cream cheese mix. The cream cheese mix normally has a butterfat content of from about 10% to about 14%. After processing, the finished cream cheese has a butterfat content of from about 33% to about 35% by weight.
The cream cheese mix is pasteurized and homogenized after which it is cooled, usually to a temperature between 62.degree. F. and 92.degree. F. and is then inoculated with a lactic acid culture. Rennet may be used to aid in the coagulation of the mix. The mix is held at the inoculation temperature until it has ripened and a coagulum is formed. The acidity of the coagulum is from about 0.6% to about 0.9% (calculated at percent equivalent lactic acid).
After the desired acidity is obtained, the curd is separated from the whey and is thereafter packaged. One well known process for making cream cheese and separating cream cheese curd from whey includes a mechanical separation of the curd. The process is disclosed in U.S. Pat. No. 2,387,276 to Link. In accordance with the method of the Link patent, after the mix is ripened to form a coagulum, the coagulum is heated to an elevated temperature to break the viscosity of the mix. Thereafter, the heated mix is centrifuged at the elevated temperature to separate the curd from the whey.
There have been many efforts to provide a cream cheese type product which has the texture, smoothness and organoleptic properties of cream cheese, but with reduced levels of fat. With increasing consumer awareness, the focal point is on reducing fat and calorie consumption. Low fat, low calorie foods which look and taste similar to their full fat, higher calorie counterparts are eagerly sought by the consumer. Researchers in the food industry have concentrated on developing food products which are nutritious and palatable, containing substantially reduced levels of high calorie, fat containing ingredients. This is particularly true in the dairy industry where low calorie, low-fat products such as skim milk, yogurt and reduced fat ice cream have been successfully marketed.
The high fat levels in some dairy products, such as cream cheese, which has a fat content of at least about 33%, have been thought to be necessary to maintain a desirable creamy mouthfeel and to avoid the grainy texture associated with prior attempts at producing low fat cream cheese products.
Recently, two methods have been developed for producing non-fat cream cheese, these methods being set forth in U.S. Pat. No. 5,079,024 to Crane and U.S. Pat. No. 5,180,604 to Crane, et al.
In the method of the '024 Crane patent, a source of concentrated skim milk is introduced into a first mixer provided with agitation means. The skim milk is agitated as the skim milk is heated in the first mixer to a first predetermined elevated temperature. An emulsifier salt is added to the skim milk in the first mixer. After reaching the first predetermined elevated temperature, the skim milk is transferred to a second mixer provided with agitation means. A first gum is added to the heated skim milk in the second mixer to provide a thickened skim milk. The thickened skim milk is homogenized in a first homogenizing step. The homogenized skim milk is transferred to a third mixer provided with agitation means. A bulking agent and a second gum are added to the homogenized, thickened skim milk in the third mixer. The homogenized, thickened skim milk is agitated in the third mixer as the skim milk is heated to a second predetermined temperature to provide a non-fat cream cheese precursor. The non-fat cream cheese precursor is homogenized in a second homogenizing step to provide a non-fat cream cheese type product.
In the method of the '604 Crane, et al. patent, a fermented skim milk retentate is introduced into a mixing tank provided with agitation means. The skim milk retentate is agitated and transferred through a recirculating loop as dry cottage cheese curd and an emulsifying salt are added to the mixing tank. Agitation and recirculation are continued for a period of time sufficient to provide a dispersion of the dry cottage cheese curd and emulsifying salt homogeneously throughout the retentate. Heating of the dispersion is then started by injecting steam into the dispersion as it passes through the recirculating loop. While the temperature of the dispersion is within the range of from about 70.degree. F. to about 150.degree. F., non-fat dry milk is added to the dispersion. Agitation and heating is continued until the dispersion temperature is within the range of from about 140.degree. F. to about 165.degree. F. Xanthan gum, as the first gum of a stabilizing system, is then added to the mixing tank. Agitation and heating is continued until the dispersion temperature is in the range of from about 165.degree. F. to about 190.degree. F. The steam is shut off and salt, sugar and carrageenan, as the second gum of a stabilizer system, are added to the mixing tank. Agitation is continued for a period of from about 1 to about 4 minutes to provide a non-fat cream cheese mix. The non-fat cream cheese mix is then homogenized to provide a non-fat cream cheese product.
While the methods of the two above-described patents have been found to produce a very acceptable tub type cream cheese product, there have been problems connected with producing a brick type cream cheese product. For the tub type non-fat cream cheese product, the tubs are hot packed with the non-fat cream cheese product, loaded onto pallets and placed in a cool room, maintained at a temperature of about 45.degree. F. Cooling of the product from the temperature at which it is hot packed to a temperature of 45.degree. F. can take as long as four days.
Brick cream cheese is conventionally made from full-fat cream cheese by using a chill roll for cooling the full-fat cream cheese. The hot cream cheese from the cream cheese make process is poured as a thin layer on the chill roll which is maintained at refrigeration temperatures. The cream cheese is doctored from the chill roll and is passed through an auger where it is subjected to shear. The product is then packaged into bricks. In another method for making full-fat cream cheese, the cream cheese is hot packed into brick packages. The brick packages are stacked onto a pallet and the pallets are placed into a cold room maintained at a temperature of about 45.degree. F. The temperature of the cream cheese is gradually reduced to about 45.degree. F. over a period of about 5 days.
Attempts have been made to use the chill roll method to make a brick cream cheese from the non-fat cream cheese produced by the methods of the '024 Crane patent and the '604 Crane, et al. patent. The absence of fat in the non-fat cream cheese products of the '024 Crane patent and '604 Crane, et al. patents prevents the product from blending well in the auger. The shear in the auger makes the product soft, airy and easily deformed when packaged into bricks. The pallet method of cooling also produces non-fat brick cream cheese with inferior body and textural properties.
Accordingly, it is a principal object of the present invention to produce an improved brick cream cheese product.
Another object of the present invention is to provide an improvement in the '024 Crane patent and '604 Crane, et al. patent to permit the methods of these patents to be used to produce a brick cream cheese product.